This important and illuminating book focuses on Ratzinger's status as one of the preeminent Catholic theologians of the 20th century. Aidan Nichols provides a full-scale investigation of his theology as it develops from the 1950s onward. The book presents a chronological account of the development of Ratzinger's writing which reflects a wide range of historical and theoretical interests such as: Augustine's ecclesiology, early Franciscanism and the idea of salvation history, Christian brotherhood, the unfolding of the Second Vatican Council, the Apostles' Creed, explorations of the concept of the Church, preaching, liturgy and Church music, eschatology, the foundations of dogmatic and moral theology, and the problem of pluralism.

This third edition, as well as providing a two-chapter-long biography of Joseph Ratzinger/Benedict XVI, and amplifying the account already given of his later pre-papal writings, describes the new thinking that belongs to the years of Benedict's pontificate. That comprises his trilogy of books on Jesus of Nazareth, his quartet of encyclicals, and the set of major speeches he gave at global venues, chiefly on the contribution of faith to culture and civil society. An expanded Conclusion, weighing the lasting significance of his work, leads into a presentation of the themes of his posthumous essay collection - the 'curtain-call' he entitled 'What is Christianity?'